Flexible endoscopes are used in numerous and different medical procedures, including gastroenterology, and manufactured by different companies. Examples of flexible endoscopes include a flexible gastroscope, colonoscope, duodenoscope (ERCP), and sigmoidoscope. Another related but somewhat different flexible endoscope is an inter bowel endoscope used in small bowel and intestinal procedures.
Endoscopes are complex and expensive medical instruments and may include an internal light source to view hidden parts inside the human body. However, even with these benefits, endoscopes have been traced to many healthcare-associated disease outbreaks due to improper cleaning after use, followed by subsequent use in a new patient. Flexible endoscopes, especially by virtue of the different body cavities they are used to visualize, acquire high levels of microbial contamination and bioburden during use, and thus, proper cleaning between uses is essential. Cleaning flexible endoscopes, however, can be challenging because the devices are usually very heat-sensitive and cannot be sterilized under high heat conditions. Instead, flexible endoscopes must be properly cleaned following each use by hand and then subjected to high-level disinfection.
Usually a flexible endoscope is pre-cleaned immediately after use and wiped down with a detergent-soaked cloth. Detergent often is aspirated with air through a suction channel. The endoscope is flushed and then channel brushed, especially in those endoscopes having elevators or auxiliary-water feeding. A water-resistant cap is attached to protect parts of the videoscope portion of the endoscope. Leakage testing may optionally occur followed by manual cleaning in a tank with a prepared detergent solution. External surfaces are cleaned by brushing. The device is aspirated with detergent, followed by soaking and rinsing and then flushed with clean water through all channels, followed by flushing air through the channels. Excess moisture is removed from the endoscope and any cleaning accessories. During this process, the endoscope may be manually transported to a washer/disinfector for a 20 to 30 minute cleaning to produce a clean and highly disinfected flexible endoscope. Upon completion of that process, the flexible endoscope is usually manually transported and placed inside a storage cabinet, which may also operate as a drying cabinet for recently processed endoscopes.
There are many different types of endoscope storage cabinets available for use. Most provide an ambient ventilated inner chamber where the flexible endoscopes are stored. HEPA filtered air is blown around the endoscopes to dry their exterior surfaces. Often separate tubes are connected to the different valve ports on the control (or valve) body of the endoscope to blow air into the various channels and facilitate their drying. The holding capacity of these cabinets vary, but range from holding 6, 10, 16, or 20 endoscopes. They usually have some type of lighting and a locking mechanism on the cabinet door together with a system to keep track of the endoscopes and any associated data.
Often the endoscopes are hung on hooks or held in position within the cabinet by some other mechanism that usually is adjacent to or positioned on the rear interior wall of the cabinet. In those storage cabinets that do not provide the capacity for air flow into the various channels of the flexible endoscope, the endoscope cabinet should include a source of HEPA filtered air to provide a positive air pressure and accommodate air circulation around the endoscopes. To enhance drying and minimize the chance of bacterial build-up within the endoscope, they are usually stored with the valves opened and any removable parts detached. The endoscope is stored so that the removable parts can be tracked with the specific endoscope and maintained in close proximity to the endoscope to which they belong. Usually some type of endoscope tracking system identifies which flexible endoscope is to be processed and used next and when it is installed or removed from the cabinet.
Although many endoscope storage cabinets provide for ambient HEPA air to be circulated around the outer surface of the endoscopes, more recent cabinet design have the capacity to pump air through the various endoscope channels. This helps keep the scope dry, and from a microbiology perspective aids in preventing moisture build-up. The absence of moisture prevents replication of bacteria and prevents the formation of a biofilm. One problem associated with some storage cabinets that do circulate air through various endoscope channels is those endoscopes are coiled and touch the base of the cabinet. Those locations of contact act as microbial growth centers. Even if the endoscopes are hung vertically where the distal tip hangs freely in a well-ventilated, clean area, a portion of the scope such as the control body may still be clamped tightly creating a possible bacterial growth center while multiple identification tags or labels that are affixed to the endoscope near the control body may add to possible contamination issues.
Even those cabinet designs, however, that minimize contact of the endoscope with the interior surfaces of the cabinet and provide a good flow of HEPA filtered air around the scope and within its channels are often designed such that it is difficult to install and remove endoscopes from the cabinet. Endoscopes are long and usually include a light guide connector connected to a flexible light guide tube, which in turn, connects to the control body (valve body). The insertion tube extends from the control body, which may include suction and air/water valves and distal from those valves could be an instrument channel port, thus adding to the overall length. When hanging vertically in a cabinet, the control body is often positioned at least 6 feet from the floor of the cabinet. This height often makes the control body inaccessible or difficult to reach. This is especially critical if tubes have to be connected to valve ports on the control body and other portions of the endoscope must be positioned correctly on a hangar or clamp. Many staff members must step or reach up to grasp the head or control body of the endoscope. Some individuals may even have to stand on a step stool to retrieve the endoscope, inviting a host of potential staff injuries.